viii Proceedings. {December 2nd, igo2. 



Ordinary Meeting, December 2nd, 1902. 



Charles Bailey, M.Sc, F.L.S., President, in the Chair. 



The thanks of the menabers were voted to the donors of the 

 books upon the table. 



Mr. Frank Southern, B.Sc, exhibited and remarked upon a 

 Japanese magic mirror 



Dr. C. H. Lees showed a small piece of apparatus used by 

 him in the determination of the thermal conductivities of solids 

 over wide ranges of temperature. It consists in principle of a 

 differential hydrogen thermometer, one bulb of which is heated 

 by an electric current either in a fiat strip of metal wound round 

 it or passing through the material of the bulb itself. 



Mr. C. L. Barnes, M.A., showed a number of experiments 

 depending on Hawksbee's law, viz., that the pressure on the 

 walls of a tube containing a fluid is less when the fluid is in 

 motion than when it is at rest. Several of these are well known, 

 e.g., the apparent attraction which results when a current of air, 

 radial or other, passes between two parallel discs, and the 

 suspension of a ball on a jet of air or water. Other illustrations 

 of the principle are that it is impossible to blow a celluloid ball, 

 or even an inflated toy balloon, out of a funnel held in the 

 ordinary upright position, though, if the funnel be reversed the 

 ball or balloon can be supported without difificulty. Also, if a 

 couple of celluloid balls are placed on a kind of railway made 

 by fastening two rods to one another, they cannot be separated 

 by blowing between them. The experiment of forcing a 

 celluloid ball out of a tall glass cylinder by blowing downwards 

 upon it was also performed, as were also several others of a 

 similar character. 



